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Canon EF 2x III Extender

Multiplies select telephoto lens's focal-length by 2X

Item #: 280EF2X

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Get some extra versatility from your telephoto L-Series lens with this precision-designed 2.0X extender. Your 300mm lens, for example, will double in reach, with a resulting focal length of 600mm (on full-frame cameras) or 960mm (on APS-C sensor cameras), once this extender has been placed in the light path. And it will only give up two stops of light sensitivity in the process. It's like getting two lenses out of your kit bag when this extender is standing at the ready.

A built-in microcomputer facilitates communication between lens, extender, and camera body, and provides fully integrated exposure and focus control on many Canon lenses. Not all lenses will be fully compatible though, so you should check your manuals and the Canon website to make sure of your lens's compatibility with this extender.

Fluorine coatings on the extender's optical elements will keep soils, smearing and fingerprints to a minimum. And it features rugged dustproof and water-resistant construction.

Product Highlights:

  • increases focal length by 2.0X on select Canon L-series telephoto lenses
    • example: a 300mm prime lens will have its reach doubled to 600mm while only losing two stops of sensitivity
    • multiply your lens's focal length by 2 to see the resulting focal length when this lens is placed in-line on a full frame camera
    • then multiply that result by 1.6 to see your effective focal length on Canon APS-C cameras
  • rugged dustproof and water-resistant construction
  • on-board microcomputer regulates communication between camera, extender, and lens
  • 9 elements in 5 groups
  • only compatible with select L-Series lenses; not all automatic functions will be accessible on all lenses, consult manuals and Canon's website for compatibility info
  • 2-7/8" (diameter) x 2-5/8" (length)
  • 11.5 ounces
  • warranty: 1 year
  • Our 60-day money-back guarantee

Canon EF 2x III Extender Reviews

Average Customer Review:

3 Reviews


Written by: Canon Fan from Ohio on January 10, 2016

This is a superb extender which works flawlessly with the Canon prime telephoto and super telephoto lenses. I bought it to supplement my Canon 300 mm f/2.8 IS II lens to give me an effective 600 mm f/5.6. The combination is light enough to hand hold and WAY cheaper than the 600 mm f/4 prime alternative offered by Canon. I am extremely pleased with the extender; I honestly can't see any degradation in the image quality when used with a Canon 5 d mk III body. Everything is corner to corner crisp and sharp and I see absolutely no sign of any contrast reduction in the images. It will also work very well with the popular 70-200 f/2.8 IS II although there is a very slight reduction in sharpness at the 70 mm end of this lens combination; the 200 mm end image quality is extremely good. If you own any of the Canon "big white" prime telephoto lenses, this is definitely a worthwhile accessory.

Pros: Very cost effective way of increasing your telephoto reach. It's very light and compact.

Cons: Loss of two stops of light compared with the mated lens.

Excellent extender!

Written by: Starphotog from Alabama on October 4, 2015

Crutchfield Customer Review (What's this?)

Excellent build and quality! Images are crisp and clean!

Pros: Excellent build and image quality

Cons: Heavy- bulky


Written by: JUNIOR from MUEFREESBORO, TN. on March 15, 2014



Cons: NONE

Hands-on research

What's in the box?

Download owner's manual

  • Extender EF2x III lens adapter
  • Front body cover (installed)
  • Rear lens cap (installed)
  • Lens Case LP811
  • Quick Guide
  • Warranty Card

Product Research


Overview: The Canon Extender 2x III will extend the focal length of a lens by a factor or 2x. It has a standard Canon EF-mount, and is compatible with many L-series Canon EF lenses (see list below). It features 9 elements in 5 groups, and comes with a soft LP811 lens case.

Compatibility: The Extender 2x III is compatible with the following Canon lenses:

Compatible Lens Focal Length and Maximum Aperture
with EF2x III
EF135mm f/2L USM 270mm f/4
EF180mm f/3.5L Macro USM 360mm f/6.7
EF200mm f/2.8L USM 400mm f/5.6
EF200mm f/2.8L II USM 400mm f/5.6
EF200mm f/1.8L USM 400mm f/3.5
EF200mm f/2L IS USM 400mm f/4
EF300mm f/4L USM 600mm f/8
EF300mm f/4L IS USM 600mm f/8
EF300mm f/2.8L USM 600mm f/5.6
EF300mm f/2.8L IS USM 600mm f/5/6
EF400mm f/5.6L USM 800mm f/11
EF400mm f/4 DO IS USM 800mm f/8
EF400mm f/2.8L USM 800mm f/5.6
EF400mm f/2.8L II USM 800mm f/5.6
EF400mm f/2.8L IS USM 800mm f/5.6
EF500mm f/4.5L USM 1000mm f/9.5
EF500mm f/4.5L IS USM 1000mm f/8
EF600mm f/4L USM 1200mm f/8
EF600mm f/4L IS USM 1200mm f/8
EF800mm f/5.6L IS USM 1600mm f/11
EF100-400mm f/4.5-5.6L IS USM 200-800mm f/9.5-11
EF70-200mm f/4L USM 140-400mm f/8
EF70-200mm f/4L IS USM 140-400mm f/8
EF70-200mm f/2.8L USM 140-400mm f/5.6
EF70-200mm f/2.8L IS USM 140-400mm f/5.6
EF70-200mm f/2.8L IS II USM 140-400mm f/5.6
EF300mm f/2.8L IS II USM 600mm f/5.6
EF400mm f/2.8L IS II USM 800mm f/5.6
EF500mm f/4L IS II USM 1000mm f/8
EF600mm f/4L IS II USM 1200mm f/8
EF1200mm f/5.6L USM 2400mm f/11

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